Help me in solving LBJ201A problem

My issue

My code

// Step 1: Read and understand the problem statement and sample test cases

// Click on 'Next' once you are ready to proceed.
import java.util.Scanner
class codechef
{
    public static void main(String args[])
    {
        Scanner Sc=new Scanner(system.in);
        int A=int.nextInt();
        int B=int.nextInt();
        int C=int.nextInt();
        for()
    }
}

Learning course: Java for problem solving - 1
Problem Link: CodeChef: Practical coding for everyone

@lavanyamallela
take input of A and C and then if both are even or odd then answer will be (A+C)/2 else it will be -1